Tunnel kiln charging and discharging means



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Patented Sept. 19, 1950 TUNNEL KILN CHARGING AND DIS- CHARGING MEANS George N. Jeppson, Worcester, and Edward Van der Pyl, Holden', Mass., assignors to Norton Company, Worcester, Mass., a. corporation oi.'

Massachusetts Application May 10, 1947,Serial No. 747,169

6 Claims.

` signed to the same assignee as the present application.

One object of the invention is to increase the rate of production of vitried grinding wheels.

Another object is to enable vitrified grinding 51j wheels to be manufactured more cheaply.

j Another object of the invention is to provide 'apparatus for the continuous vitrifcation of Another object is to provide apparatus which will greatly reduce the labor required for manufacturing vitrlfled grinding wheels.

Another object is to provide a highly elcient and easily operated continuous kiln. Another object is to eliminate cars with wheels or thelike in a tunnel kiln. Another object is to provide a tunnel kiln and equipment therefor in which everything passing through the firing zone and in the firing zone is made out of non-metallic refractory material, thus eliminating sand seals and the like and reducing the height and the mass of the kiln. Another object is to reduce the cost of operating a tunnel kiln both for repairs and for labor. Another object of the invention is to provide a fully automatic tunnel kiln with conveyors so that when loads of ware are, deposited at a loading station, they will be picked up, one load at a time, put through the kiln and removed, one load at a time, and co1- lected at a receiving station. Another object is to provide a dependable kiln loading mechanism operatingat adjustable time intervals.

Other objects are to provide tunnel kiln conveyor mechanism including loading, feeding, charging and discharging apparatus, which will operate automatically in repeating cycles, with interlocking controls so that the cycle will be interrupted if anything goes amiss, and with safety devices to prevent accidents. Another object is to provide 'a tunnel kiln and operating mechanism, in which everything in or near the tunnel is entirely refractory. Another object is to provide entirely refractory ware conveying apparatus together with propelling mechanism therefor which is throroughly reliable in operation.

Other objects will be in part obvious or in part pointed out hereinafter.

The invention accordingly consists in the features of construction, combinations of elements,

and arrangements of parts, all as will be illustratively described herein, and the scope of the application of which will be indicated in the following claims.

In the accompanying drawings illustrating a tunnel kiln and automatic mechanism for propelling the ware (green grinding wheels to be vitriiied) through the kiln.

Figure 1 is a verticalsectional view of the discharging conveyor for removing the batts (which hold the ware) from the exit end of the kiln, most of the parts, however, being shown in elevation.

Figure2 is a fragmentary vertical central sectional view on an enlarged scale of the entrance end and preheating zone of the kiln showing also the elevator for raising the batts to the kiln tunnel level and the propelling or charging mechanism for intermittently propelling the batts through the kiln.

Figure 3 is an elevation of the front end of the batt propelling ram, the view being taken from the line 3-3 of Figure 2 looking in the direction of the arrows.

Figure 4 is a fragmentary vertical sectional view oi the kiln showing the annealing zone and exit end, the scale being the same as that of Figure 2, the view also showing part of the discharging conveyor in elevation.

Figure 5 is a fragmentary elevation of a batt and a cross sectional view of a refractory rod on a large scale.

Figure 6 is a fragmentary side elevation of a pair of batts showing the interlocking thereof, on

Va scale larger than that of Figure 5.

Figure 7 is a transverse (nearly vertical) sectional view through the kiln taken on the line 1--1 of Figure 2 on the same scale as that iigure.

Figure 8 is an elevation of conveyor mechanism at the entrance end of the kiln,` showing the feeding conveyor and the elevator, the ram piston and ram cylinder support being shown in section.

Figure 9 is a plan view of the outer end of the feeding conveyor and ofthe transferrer, where the batts are transferred from the loading conveyor to the feeding conveyor.

Figure 10 is a vertical sectional view of the feeding conveyor and the elevator, the section being taken on the line Ill-I0 of Figure 2.

Figure 11 is a vertical cross sectional view of the feeding conveyor taken on the line II-II of Figure 10.

Figure 12 is a vertical cross sectional view of the elevator taken on the line |2-I2 of Figure 10.

Figure 13 is a side view with certain parts shown in section taken on the line I3-|3 of Figure 8, of theentrance endv of the kiln, `showing a batt on--theelevator (in dash-dot lines) actuating an'electrlcal-swltch. Figure- 14 is .an axial sectional view of the sprockets for the feeding conveyor, 'the section being taken on the line M-II of Figure 10.

Figure 15 is a sectional view on an enlarged scale taken on the line ||5 of Figure 2 showing the bumper to stop'the batts on the feeding conveyor in position to be picked up by the elevator.

Figure 16 is a sectional view taken on the line Iii-I8 of Figure 9 showing the bumper and switch support to stop the batts over the feeding conveyor as they are transferred thereto by the loading conveyor.

Figure 1'7 is a sectional view taken on the line |1-I1 of Figure 9 showing a support for an electrical switch.

Figure 18 is a sectional view on an enlarged scale taken on the line |8I8 of Figure 8 showing the trunnion support for the transferrer actuator.

Figure 19 is a sectional view on the same scale as Figure 18 taken on the line |8-l9 of Figure 8 showing another part of the transferrer actuator.

Figure 20 is a side elevation of the loading conveyor.

Figure 21 is,a plan view on an enlarged scale of the loading conveyor adjacent the feeding conveyor, also showing the transferrer in dashdot lines.

Figure 22 is a vertical sectional view taken on the line 22-22 of Figure 2i, showing the feeding conveyor and elevator in full lines.

Figure 23 is a vertical sectional view taken on the line 23-23 of Figure 22 showing the transferrer and part of the actuator therefor.

Figure 24 is an hydraulic diagram including axial sectional views of the piston and cylinder charging and propelling mechanism and ram, the piston and cylinder mechanism for the elevator and the control valves for each.

Figure 25 is an electrical diagram showing how the various switches control the conveyors, the transferrer, the elevator and the charging and propelling mechanism.

Referring first to Figures 2, 4 and 'I the kiln, which is generally indicated'by the number 2U, is mounted on a plurality of legs 2| which may be made of steel. As shown, the kiln 20 has the shape of a parallelepiped which is rectangular in cross section, but the ends need not be perpendicular to the top and bottom of the kiln 20 since it is inclined to the horizontal. The pitch of this inclination was actually about one foot in twentythree, which is an angle of about 228. Preferably it should not be much less than say 2', nor much greater than 8. The purpose of the downward pitch, for in Figure 2 the right hand end of the kiln is the entrance end, is to drive more of the hot gases toward the entrance end of the kiln; some gases go to the annealing zone and this is desired.

Referring again to the aforementioned figures, the kiln may comprise sheet steel bottom plates 22, sheet steel top plates 23 and sheet steel side plates 2l, all fastened together to form the elongated box like structure shown by means of many angle irons 25 as well as the upper portions of thelegs 2| and tie rods 28, the foregoing metal uparts being bolted together or welded together or partly bolted and partly welded as desired. Referring to Figure 2, an entrance end plate 30 paruyrcovers-thefentranee end or thegkiiri and referring to Figure 4, van exit end plate 32 partly coversvthe exit end of the kiln; these plates likewise are preferably made of vSh'eetstee'land may -be welded to angle irons 25; they do not cover the ends of the tunnel 35.

One of the features of the invention is the relatively small size of the kiln. While it may be profitably made in much larger sizes, the kiln actually built was 23 feet, 3 inches long, measured on the horizontal, and 2 feet '1 inches square in cross section measured between the insides of the sheet metal plates.. The chief reason for the legs 2| was to place the tunnel 35 high enough for working convenience, the bottom of the exit end of the kiln being 2 feet above the fioor and of the entrance end being 3 feet above the floor. This kiln can vitrify wheels up to eight inches in diameter and two inches thick For larger wheels-larger kilns should be constructed.

Still referring to the same figures, the kiln 20 contains a refractory lining 36 which insulates and defines the tunnel 35. This lining may be constructed in a number of ways. but the illustrative embodiment herein illustrated is highly practical, readily constructed and easily repaired. The bottom bricks of the lining 36 have aligned pairs of rectangular grooves 48 in their upper surfaces thus forming at the bottom of the tunnel 35 a continuous groove on each side thereof extending from end to end of the tunnel, the grooves 48 being separated by ledge portions 50.

Referring now to Figures 2, 4 and '1 we provide refractory supporting members 15 in the rectangular grooves 48 which collectively fill the corresponding grooves 48 fromend to end of the tunnel 35. Slight gaps are left between the members 15 for expansion. Each supporting member 15 has a V groove 16 in its top and bottom. In these V grooves 16 on the upper side we place refractory rods 11 which, as best shown in Figure 13, have tapered end portions 18. The reason for the grooves 16 on the bottom of the members 15 is to make symmetrical pieces in order to avoid warping in firing or in subsequent use. Referring now to Figures 2, 4, 5 and 6 we provide ware carrying refractory batts 88 which are thin rectangular plates of refractory material having thickened ends 8| with grooves 82 on the under side extending across the batts and locating the batts on the rods 11. The upper side of each batt is at and has a layer 83 of silica. The sides of the batts 80 have respectively projections 84 and grooves so that the batts are interlocked together in the tunnel 35. This keeps any batt from riding over the batt in front and also has other advantages which will be hereinafter pointed out.

The supporting members 15 and the rods 11 are preferably made of self bonded aluminum oxide. Thus they are highly refractory and resistant to wear. The batts 80 are preferably made of vitriiled silicon carbide which is still more refractory and wear resistant. The silica layers 83 are formed by placing layers of silica cement on the batts and then vitrifying. These layers 83 prevent contamination of the ware, especially when the ware is made of aluminum oxide abrasive particles with ceramic bond as is frequently the case. The rods 11 are preferably ground to produce smooth accurate cylindrical surfaces and the grooves 16 are also preferably ground.

We have found that batts 80 having green wheels and partly vitrifled wheels and vitried Wheels undergoing annealing in a long continnous line can be forced through the tunnel 35 by a thrust at the entrance end, and the batts stay in perfect alignment, nothing is broken and the ware is not disturbed in any way.` The grooves 62 in the batts 66 by coaction with the rods 11 help to maintain the batts parallel and in alignment. The thrust is intermittent and is applied to each batt as it enters the kilnthe new batt transmits the thrust to the next in line and so on, each batt transmitting the thrust to the one in front of it until the batt at the tunnel exit end is reached, which has no batt in front of it, for batts which have passed out of the kiln are removed by automatic machinery as will be described. 'I'his means of propelling batts through the tunnel 35 is entirely successful despite the fact that no rollers or metal parts are used. The tapered end portions 19 have proved eiective in preventing the batts from catching on the rods 11 despite the fact that the rods are not continuous. These rods 11 can be replaced in the tunnel 35 even when the kiln is hot, for they can be pushed along the grooves 16 and will not catch in the joints between supporting members 15. Since the rods 11 are round they have many sides orareas for successively taking the wear, new areas being placed uppermost merely by turning the rods. An unexpected and surprising fact about the action of the batts 86 on the rods 11 is that the wearing of the rods 11 is greater in the annealing zone than it is in the heating zone.

We provide a ram |59 to push the batts with a steady stroke of measured length, This ram may be operated by any suitable mechanism, intermittently actuated; we have found it convenient to employ a cylinder and piston unit using the city water supply for power. We further provide a feeding, conveying and transferring mechanism and while this mechanism may be varied within wide limits, a good practical apparatus which was actually used will now be described.

In Figure 20 there is shown a loading conveyor |66 upon which the batts 86 with green ware may be placed at spaced intervals, and no very accurate spacing is required. Next in line is a feeding conveyor |6| (Figure 8) which extends at right angle to the loading conveyor |66 and receives batts from it. This feeding conveyor |6| moves batts, one at a time, from the loading conveyor to an elevator |62 (see Figure 12, for example) which raises them, again one at a time. to a position in front of the ram |59. As the ram |59 operates, a batt 86 emerges from the exit end of the kiln. It lands upon a discharging conveyor |63 which moves a small distance and then stops. At the end of the discharging conveyor |63 is a roller table |64 upon which the batts with red ware may collect until an operator removes the batts and places the red wheels or other ware in a box for shipment to a customer.

The sequence of operation of this mechanism is as follows: During a considerable period of time. (about three minutes) the ram |59, the loading conveyor |66, the feeding conveyor |6|, the elevator |62 and the discharging conveyor |63 are all at rest. The ram |59 is retracted (as shown in Figure 2) and the elevator |62 is down. There is a batt 66 upon the feeding conveyor |6| just over the elevator and another batt 66 over the feeding conveyor |6| right in front of the loading conveyor |66 and there may be one or more batts 86 between these stations. There may be a number of batts with green wheels upon the loading conveyor and a number of batts with fired wheels upon the discharging conveyor |63 and possibly some upon the table |64 (depending upon the activities of the operators). Presently a timing mechanism starts the operating cycle. The elevator |62 rises and stops. The ram |59 then slowly advances pushing the new batt 56 into the entrance end of the tunnel 35 and pushing all of the batts in the tunnel a distance of the width (dimension along the tunnel) of one batt. This results in one batt 66 with fired wheels leaving the tunnel 35 whereupon the discharging conveyor |63 starts moving and then stops after having moved a short distance. All of the batts thereon are moved this distance (including the one which just emerged) and if there was one near the table |64 it slides upon it, perhaps pushing some others ahead of it.

When the ram |59 has completed its forward stroke, it retreats a full stroke. Then the elevator |62 moves down to its bottom position. Now the feeding conveyor |6| operates until the nearest batt 66 upon it has been moved to above the elevator |62, whereupon the feeding conveyor |6| stops. At this time the loading conveyor |66 operates and moves a batt with green ware over the feeding conveyor |6|, whereupon the loading conveyor |66 stops. The transfer from the loading conveyor |66 to the feeding conveyor |6| is effected by the use of a transferrer or mechanical switch |65 (Figure 6). Now the various conveyors and the elevator |62 and ram |59 remain at rest for a period of time until the timing mechanism again starts the cycle.

Of the mechanisms whose action has been above outlined we shall nrst describe the ram |59 and its hydraulic actuating mechanism. Referring now to Figures 2, 3 and 24, the ram |59 is a disc shaped piece of metal set on edge with part of the bottom cut off and having a screw threaded hub |16 by means of which it is screwed on to the threaded end |1| of a piston rod |13 which extends through a cylinder head |14 into a cylinder |15. The cylinder head |14 has a suitable stuffing box |16 to minimize leakage. which may be tightened by a stufling box nut |11. The cylinder |15 is further provided with a solid cylinder head |16. Channels |19 and |66 in the heads |14 and |16 respectively admit and exhaust fluid (as water) to drive a piston |8| on the rod |13. This is the mechanism for intermittently propelling the batts 66 through the kiln 26. 'I'he actuation of the piston |6| will be later described.

The cylinder |15 may be supported in any suitable manner, but as herein shown a large box structure |65 made of sheet metal has a ledge |66 which supports the cylinder head |14 while a post |81 supports the cylinder head |16. The box |65 has an open bottom and a side opening through which the batts 66 can enter; it is also open on the sidefacing the entrance end of the kiln tunnel 35 but extends to it and helps to keep the heat in the tunnel 35. The piston rod |13 extends through a hole in the box |65 and the ram |59 moves back and forth in the box |65 which is supported by angle iron legs |9|.

Figure 20 illustrates the loading conveyor |66 and Figure 21 shows that end of the loading conveyor which is next to the feeding conveyor |6| and the transferrer |65. A plurality of angle iron legs are connected by lower vframe members |96 and |91 and upper frame members |96 and |99, these several frame members beingv horizontal. The legs |95 and some supports 266 and 20| extending upwardly from the frame members |98 and |99 respectively, support a pair of long steel girders 203. These girders 203 form the conveyor frame and they are cross connected by steel plates 204 at intervals, also by angle irons 205 at the legs |95 and the supports 200 and 20|. Journalled in the girders 203 and extending between them are a plurality of rollers 2|0 located at evenly spaced intervals. These rollers 2|0 are adjustably fixed in position, and they are freely rotatable. Upon these rollers 2|0 rests the upper course of a long endless belt 2|I. Another set of rollers 2I5 rest upon the upper course of the belt 2| I. These rollers 2|5 which, as will be seen. are more numerous than the rollers 2|0, are free to move up and down within limits, but not forward and back, and they are revolved by the belt 2|| whenever it moves. As shown in Figure 22, the rollers 2|0 and 2| 5 are hollow metal cylinders and are journalled on ball bearings 2|1 supported by .hexagonal shaped rods 2|6. The rods 2|8 supporting the rollers 2|0 are fastened to plates 2 I9 which are fastened to the girders 203 by means of bolts 220 passing through vertical slots 22| in the girders 203. The ends of the rods 2 I8 that support the rollers 2|0 are located in vertical slots (not shown) in plates 223 that are attached to the girders 203. A pair of rollers 2|5a and 2| 5b shown at the right hand end of Figure 21 have reduced portions 226 at the center over which passes a belt 221 whereby the roller 2I5a which is driven by the belt 2|I will drive the roller 2| 5b. Otherwise these rollers l2|5a and 2|5b and their mountings are the same as the rollers 2|5 and their mountings.

The batts 80 with green ware are placed upon the rollers 2I5 with the long dimension of each batt parallel to the axes of the rollers 2|5. Consequently the batts will move along the loading conveyor |60 whenever the rollers 2|5 rotate, which is whenever the belt 2II is moved. An electric motor 230 has a reduction gear unit 23| which drives a sprocket 232 which drives a sprocket chain 233 which drives a sprocket 234 which is fastened to a large drum 235 over which the belt 2II passes. The drum 235 is iournalled in journal supports 236 supported by the frame member |69 while the motor 230 and reduction gear unit 23| are supported by the frame member |91. The belt 2|| passes over an idler drum 240 at the end of the conveyor I 60 opposite the end where the drum 235 is located, this drum 240 being journalled in journal supports 24| supported by the frame members |96. The lower course of the belt 2| I passes over idler rolls 242, 243 and 244 mounted in brackets 245, 246 and 241, the brackets 245 and 241 depending from the girders 203 and the brackets 246 being mounted on the frame members |99. The lower course of the belt 2| likewise passes under a tensioning roll 250 which is journalled in a pair of arms 25| pivotally connected to brackets 252 depending from the girders 203. A heavy weight 254 secured to the arms 25| puts tension on the belt 2|I. It will thus been seen that the batts 80 will move` along the conveyor |60 whenever the motor 230 is energized, and will stop whenever the motor 230 stops. This motor 230 is of the type having a friction brake so that it will not coast.

The feeding conveyor |6I is shown as a whole in Figure 8 and is at the left hand end of the loading conveyor |60 as viewed in Figure 20 which is the same as the right hand end of the the conveyors and kiln is as follows: If the kiln 20 extends north and south and if the entrance end of the kiln is north, the loading conveyor |60 extends north and south and the green ware is gradually moved south. The feeding conveyor I6| then extends east and west and moves the green ware. by stages. west. The ware moves south through the tunnel 35 and after it is ilred it moves south on the discharging conveyor |63.

Referring now to Figure 8, the feeding conveyer I 6I has a pair of supporting legs 260 connected by cross members 26|. These legs support girders 262 (see Figures 8, 9 and 22) which are also supported by the legs I9I that support the box structure |85. As shown in Figures 9 and 11, a number of cross members 263 tie the girders 262 together. Secured to the cross members 263 are rails 265 which are rectangular steel bars. These rails 265 stop just short of sprockets 261 and 268. The sprockets 261 are located at the left or east end of the conveyor I6I while the sprockets 266 are located at the right or west end of the conveyor |6I. See Figures 9 and 10. The sprockets 261 are mounted on a shaft 210 which is journalled in journals 21| secured to the girders 262. Referring to Figures 10 and 14 the sprockets 268 are secured by keys 213 to a shaft 215 which is journalled in journals 216 secured to the girders 262. The shaft 215 extends beyond one girder 262 and has fastened thereto a sprocket 218 by means of a key 219. Referring to Figure 8, .a motor 28| having a reduction gear unit 282 drives a sprocket 283 which is connected by means of a sprocket chain 284 to the sprocket 218. Therefore, when the motor 28| is energized, the shaft 215 will be revolved. The motor 28| is mounted on longitudinal frame members 281 supported by the legs 260 and I9I.

Long sprocket chains 290 connect the sprockets 261 and 266 as shown in Figures 8, 9 and l0 and the upper courses of these sprocket chains 290 rest upon the rails 265. The lower courses of vthe sprocket chains 290 are supported by rolls 29|, which, as best shown by Figure 11 are mounted on shafts 292 supported by brackets 293 secured to the undersides of the girders 262. The batts are supported and moved by the chains 290, and the long dimensions of the batts 80 are parallel to the chains 290 as they rest or move thereon. In fact, if these long dimensions were east and west when the batts were placed upon the loading conveyor |60, they remaineast and west on all the conveyors and in the kiln 20.

Referring now to Figures 8, 9, 16, 17, 18, 19, 20, 2l, 22 and 23, and starting with Figure 22, the transferrer |65 comprises eight idler rolls 295 and mechanism to raise and lower them. Thus when the feeding conveyor I6| is about to receive a batt 80 from the loading conveyor |60, the rolls 295 are up, in which position their tops are about on a level with the tops of the rollers 2|5. A batt 90 is driven by the rollers 2I5 onto the rolls 296 and then continues to ride thereon by its own momentum until it hits a roller 296 of a switch arm 291 (see Figure 9) of 'a switch 298. which action stops the loading conveyor |60 and thus prevents more batts 86 from riding onto the rollers 295. Later on the rollers 295 move down and the batt 80 that was stopped by the roller 296 of the switch 296 is laid upon the sprocket chains 290 ready to be moved by them. f i

Referring now to Figures 22 and 23, the rolls 295 are rotatable on shafts 300 which extend between and are supported by angle brackets 30| (there being two pairs of these brackets) which in turn are supported by two steel plates 302 extending at right angles to the girders 262. The steel plates 302 are connected and supported by a steel plate 303 extending parallel to the girders 262, and the steel plate 303 is secured by a nut 304 to a vertical shaft 305, there being an aligning and supporting head 306 through which a reduced end portion of the shaft passes, the head 306 serving to support the plate 303. It will be seen that by raising and lowering the shaft 305, the eight rollers 295 of the transferrer or mechanical switch |65 are raised and lowered. It will be noted that four of the rollers 295 are between the chains 290 and the rails 265 and it is upon these four rollers that the batts are (successively) stopped right over the chains 290.

The shaft 305, as shown in Figures 22 and 23, is mounted for vertical movement in a sleeve 309 which is secured to a horizontal plate 309 the ends of which are secured to the bottom of rectangular brackets 3|0 secured to the undersides of the girders 262 (see also Figure 8). The bottom of the vertical shaft 305 rests against a block 3|2 on the end of a shaft 3|3 which, as best shown in Figures 8 and 25, is' pivoted on a pin 3| 4 which extends through the shaft 3|3, and through a spacing block 3|5 and a pair of brackets 9I6 that are secured to a cross mem- -ber 3| 1 mounted on longitudinal frame members 3 I9 connected to the legs 260 and the nearer pair of legs |9|. As shown in Figure 8 the shaft 3|3 extends far to the right beyond the pin 3|4 and has near the'f'e'nd thereof a weight 320 adjustably secured thereon by means of a set screw 32|. This weight tends to keep the rolls 295 of the transferrer |65 in the up position, but electrical means are provided to raise the right hand end of the shaft 3| 3 and thereby to lower the rolls 295.

Referring now to Figures 8 and 19, a solenoid coil 323 is attached to a pair of cross members 324 which are supported by the longitudinal frame members 3|8. An iron core 325 in this solenoid coil 323 has non-magnetic extensions 326 between which is secured, by means of a` bolt 321, a block 328 having a slot 329 through which the rod 3|3 extends. When the solenoid coil 323 is energized, the iron core 325 is raised, which raises the extensions 326 and the block 328, which raises the right hand end of the shaft 3|3 thus loweringthe block `3|2 thus lowering the transferrer |65. This action `switches the batt 90 that is on the rolls 295 to the chains 290 of the feeding conveyor |6|.

Referring now to Figure 9 the roller 296 and a spring 330 acting against the switch arm 291 act as a. bumper to stop the moving batts 80 but it is advisable to have a pair of bumpers to avoid skewing of a batt. Consequently we provide a block 33| secured to the girder 262, the block 33| containing a spring 333 which acts on a rod 334 which bears against an arm 335 pivotedflto a bracket 336 extending from the block 33|, the arm 335 having a roller 331 which is contacted by a batt 80. Referring to Figure 22, the block 33| is secured to a plate 34| which is Welded to a vertical plate 342 fastened to the girder 262. Referring to Figure 16, the casing of the switch 290 is secured to an angle iron bracket 343 which is secured to a T-member 344 fastened to the girder 262. Referring to Figure 17, a bracket 349 having a horizontal portion 349 supports a switch 350, the bracket 349 being secured to the underside of thegirder 262. As shown in Figure 9 this switch 350 has a switch arm 35| supporting a'roller 352 which is contacted by a batt 60 as it moves over the switch 350. The purpose of this switch 350 will be hereinafter described.

VVAlthough the batts 60 should successively be placed upon the chains 290 perfectly parallel thereto and with part of each batt upon each chain, by reason of the mechanism above described, nevertheless as an additional precaution which is remarkably effective in keeping the entire apparatus running without any catastrophes, we provide alignment and equalizing mechanism which operates to straighten the batt upon the feeding conveyor |6| and/or to move them sideways so that an equal area of each batt will be upon each chain 290. Referring now to Figures 8 and 11, fastened to the cross members 263 are sheet metal guides 355 which as shown have the crosssectional shape of stairs; the top vertical portion 356 does the guiding and the leading ends of the guides are bent outwardly to form cams 351 which straighten out the batts and center them as they move along the feeding conveyor IGI.

It is important to stop each batt when the feeding conveyor has moved it that precise distance which puts it directly above the elevator |62, and it is likewise important to stop the feeding conveyor at this moment so that another batt 60 will not run into the batt that is at the elevator station. Referring now to Figures 2 and 15, we provide bumper' `arms 360 secured to the legs |9| which bring the batts successively to a positive stop without rebound and we further provide (see now also Figure 10) a switch 364 having a switch arm 365 with a roller 366 to stop the feeding conveyor |6|. The switch 364 may be secured to a panel 361 that is fastened to the box |85.

The elevator |62 is best shown in Figures 3, l0 and 12 and the hydraulic mechanism to actuate it is shown in Figure 24. Referring now to Figure 10, the elevator |62 comprises a horizontal plate 315 having on the ends thereof batt supports 316 with rounded tops. These batt supports 316 contact the batts 80 in the grooves 92. When the elevator plate 315 is up, the ram |59 can move between the supports 316 and thrust a batt 80 onto a pair of the rods 11, which project into the box |65 as shown in Figure 2. The elevator plate 315 has on the lower side thereof a boss 319 in which is located and fastened the upperend of a piston rod 380 which extends into a cylinder 39|.

The cylinder 39| is fastened by means of clamps 393 to an upright frame member 384 that is connected by a. bracket 385 to the girder 262 and by an angle iron 396 to the longitudinal frame member 291. Referring to Figure 24, the cylinder 36| has a solid cylinder head 381 at one end and a bored cylinder head 389 at the other end through which the piston rod 390 passes. In these heads are channels 399 and 390 respectively. By admitting and exhausting fluid such ananas 11 inder head 369 has a stuing box 393 tightened by a stumng box nut 394.

Referring now to Figures and 12, a rod 395 has a screw threaded portion 396 by means of which and a nut 391 it is fastened to the plate 315 near one batt support 316.' 'Ihis rod 395 passes through a sleeve 398 which is secured to a plate 399 that is fastened to vertical members 400 secured to the undersides of the girders 262. This construction keeps the elevator plate 315 from turning as it moves up and down and the rod 395 is likewise used to actuate a switch 40| (Fig. 8). As shown in Figure 8, the switch 40| has a switch arm 402. at the end of which is a roller 403 which is contacted by the end of the rod 395 when the elevator |62 is down. This switch 40| sets in operation the feeding conveyor |6|.

The return of the ram |59 sends the elevator |62 down. As shown in Figure 2, on the upper side of the ram |59 is a xed arm 405 which contacts a roller 406 on a pivoted arm 401 of a switch 406 fastened by a bracket 409 to the legs |9| inside of the box |85. This switch 408 initiates downward movement of the elevator |62. In order that the ram |59 shall not turn by turning of the piston |8| in the cylinder |15, we provide a pair of guides 4|0 fastened to the box |85 which contact the flat bottom of the ram |59 and straighten it out whenever it has started to turn.

It will be noted that the contact and supporting portions of the batt supports 316 are horizonal, see for example Figure 12. At least they were made that way but use soon puts a crown to these surfaces in a longitudinal direction since the batts 80 are abrasive. It will also be noted that the ram |59 moves parallel to the axis of the tunnel 35 but this axis is on an incline and the b"atts 80 are substantially horizontal when they are on the elevator |62. Referring to Figure 2, a pair of bricks 4|5 are supported by the kiln 20 at the entrance end of the tunnel 35, and these bricks 4|5 support refractory members 15 which support rods 11 that extend well into the box |65. The angular relationship of the parts is such that the tapered end portions 18 of these rst rods 11 are about horizontal on top. We have found that the batts go very nicely onto the rods 11 and into the tunnel 35 with this mechanical construction and actuation despite the fact that there is a slight change of direction and some resultant force normal to the plane of the rods 11. As a safety precaution, however, we provide, referring to Figures 8 and 13, hold down members 4|1 which may be shaped like an angle iron with a bottom portion 4|9 perpendicular to the apex of the angle, for the purpose of preventing the batt 60 thereunder from rising during the stroke of the ram |59. It has been found that if the batt 80 just entering the tunnel 35 is kept down, there will be no trouble with the batts ahead of it and it has been further found that under these conditions the batt which is being pushed by the ram will not rise either. However most of the time there is not even any contact between the bottom portion 4|8 and the batt under it.

Referring to Figure 13, in the box |65 and attached to it by a bracket 420 is a switch 42|. This switch 42| has a long pivoted arm 422 with a hump 423 at the end thereof, and at the ends of the hump 423 are located rollers 424 and 425.

When the elevator |62 rises, the batt 80 thereon hits the roller 424 and thereby moves the arm 422 and actuates the switch 42|. This starts the 12 ram |59 moving. By reason of the combination of the rollers 424 and 425, the switch arm 422 remains up vuntil the ram |69 has gone practically all the way forward. The rollers 424 and 426 ride upon the batt as it moves out under them.

Referring now to Figure 2. a switch 428 is fastened by means of a bracket 429 to the inside of the box and has apivoted ann 430 with a roller 43| which is contacted by the lower flat side of the ram |59 at the end of its forward stroke. This switch 426 is used when loading the kiln with empty batts pursuant to starting it in operation as will be hereinafter more clearly explained.

The discharging conveyor |63 is shown in Figures 1 and 4. It is a type of conveyor like the feeding conveyor |6| but any o1' the conveyors could be of this type or of the type disclosed in the description of the loading conveyor |60, or other types of conveyors could be used for any of the three used in this invention. Referring now to Figures 1 and 4 a pair of legs 436 at each end support a pair of girders 436 which are cross connected by members 431. Cross braces 436 parallel to the members 431 connect the legs 435 and longitudinal angle iron frame members 439 perpendicular to the braces 438 likewise connect the legs 435. Supported by the cross connecting members 431 are a pair of rails 440 upon which ride the upper courses of sprocket chains 44| extending between a pair of sprockets 442 at the kiln end of the discharging conveyor |63 and a pair of sprockets 443 at the far end of the conveyor. These sprockets 442 and 443 are respectively mounted on shafts 444 and 446 which are journalled in the girders 436. An outside sprocket (not shown but identical with the sprockets 442 and 443) is keyed to the shaft 445 and the sprockets 443 are likewise fastened to this shaft which is thereby driven with thelaid of a sprocket chain 441 extending from a sprocket 448 on the shaft 449 of a reduction gear unit 460 which is connected to a motor 45|, the unit and the motor having connected casings. This motor and reduction gearing combination is mounted on a plate 453 which rests upon the frame members 439. The lower courses of the sprocket chains 44| rest upon a roller 466 journalled in brackets 456 which are attached to the girders 436.

Thus whenever the motor 45| is energized the pair of chains 44| will be moved at a slow speed, and the upper courses of these chains move to the left in Figures 1 and 4. Any batts 80 which are resting upon the chains 44| are thereby moved to the left, and this discharging conveyor |63 is positioned to receive batts 80 discharged from the tunnel 36.

Referring to the same gures, the final rods 11a resting on the members 15 in the tunnel 35 are cut off and abutting them are pipes 456 which are welded to the girders 436. The pipes 456 thus constitute continuaticns of the rods 11a and the rods 11, and the batts 80 can ride right -onto the chains 44| and be propelled along the chains by the driving force imparted by the ram |68.

When, however, a batt 60 contacts a roller 468 of a switch arm 459 of a switch 460 the motor 46| is energized and the chains 44| start to move. This carries the batt 80 which hit the roller 458 along until it hits another roller 462 on an arm 5463 of a switch 464 which stops the motor 46|.

The conveyor |63 picks up only one batt 86 at a time from thekiln 20 since there is not room for two batts on the chains 44| back of the switch roller 458.

The switch 466 is mounted on aplate 466 which is located in between the girders 438 and the chains 44 Theswitch 464 is mounted on a plate 461 likewise centrally located. The plate 466 is welded to the top of an angle bracket 486 which is secured by a screw 469 to an upstandlng bracket 416 that is welded to a cross plate 41| resting on top of and secured to the angle iron trame members 439. Projecting guides 412 on the bracket 416 keep the angle bracket 468 from sagging and a slot 4413 through which the screw 469 passes provides for'adjustment of the switch 466 and its roller 458 longitudinally. An arm 414 -of the bracket 416 Provides a Support for the plate 481, the plate being welded to the ann.

There is a third switch 411 centrally located between the chains 44| and between the switches 466 and 464. This switch 411 starts the ram |59 moving back. It has an arm 418 with a roller 419 which is contacted by a batt -86 as the batt moves over the roller. The switch 411 is mounted on a plate 486 which is` welded to the top of the upstanding bracket 416.

We may further provide a batt collecting table |64 to collect the batts 86 as they are moved off the discharging conveyor |63, though the same result would be achieved by making the conveyor |63 long enough and providing a bumper at the end. The ware 92 may be picked off the batts 86 while they are on the conveyor |63 at any time provided the ware 92 is cool enough to be handled with or without gloves. As the ware 92 is picked off it is packed in boxes for shipment or inventory storage and the batts are returned to the loading end for reloading with green ware to be placed on the loading'conveyor |66. The collecting table |64 comprises legs 48-6 (four or more of them but only one shown) to which are secured girders 4'81 connected by cross members (not shown) and supporting rollers 496 which'may `be like the rollers 2|5 and similarly mounted. Gap bridging members 495 similar in function to the pipes 455 are welded to the girders 481 and hold the batts at the gap between the chains 44| and the first roller 496. The table 464 may be as long as desired and the batts 86 just roll out onto it until so many have collected that the chains 44| can no longer drive them ahead, whereupon they back up on the discharging conveyor |63. This combination of discharging conveyor |63 and collecting table |64 affords adequate time for the batts 86 and the ware 92 to cool enough so that they can be handled with bare hands.

Figure l shows an adjusting bracket 496' for the legs 486 whereby the height of the table |64 may be adjusted and it may be levelled despite inequalities in the floor of the building, or it may be slightly inclined if desired. The brackets 496 have long slots 491 through which extend screws 498 fastening the legs 486 to the brackets. This adjustable support feature may be adopted for any or all of the legs of the various conveyors and the kiln 26.

Referring now to Figure 25, we provide an adjustable timer 566 of any appropriate design involving a motor 56| and a resettable arm connected to the motor and reduction gearing by a gear moved into and out of mesh by an electromagnet, with a trip device actuated by the arm and a clock spring to return the arm. Many such 14 made by the Sangamo Electric Company of Springeld, Illinois. The timer 566 may be mounted in a box 5|6 on onev of the frame members 3|6, see Figure 8.

As part of the timer 566 there is an electromagnet 5|| which, when energized, moves the gear into mesh and endeavors to close a switch 5|2 and open a, switch 5|3, but the trip device of the timer prevents the latter two until it is operated by the arm oi the timer, which is moved by the motor 56| through the reduction gearing of the timer.

There is a period of time when all the conveyors, the ram |59, the elevator |62 and the transferrer |65 are stationary but the motor 56| is running. 'Ihere should then be a batt 86 above the elevator |62 as shown in Figure 10. At this time the electromagnet 5|| is energized, but the switch 5|2 remains open and the switch 5|3 remains closed because they are held by the latch of the timer.

Referring now to Figure 25, the electric power may be provided by main power lines 52| and 522. These lines 52| and 522 are connected by a main disconnect hand switch 523 to main lines 524 and 525 which in turn are connected by a hand switch 526 to main lines 53| and 532. The

electromagnet 5| is energized by a branch line devices are on the market and therefore no drawings of `such timer 566 are herein provided. The one actually used was a Sangamo timer, model 15, form 61-S1 115 volts 60 cycles 10 amperes,

533 from the line 53|, a line 534, a line 535 and a line 536 to a double throw hand switch 531, then a line 538 to the switch 468, then by a branch line 546 to the other main'line 532. The motor 56| is energizedvby branch line 533, line 54|, switch 5|3, line 542 and short line 543 to the line 535, then to the power line 532 as above stated. It will be seen that the ram |59 has to be fully retracted and holding the switch 468 closed for the timer motor 56| to operate.

Finally the timer latch is tripped by the timer arm operated by the motor 56|. Then the electromagnet 5|| closes the switch 5|2 and opens the switch 5|3. This stops the motor 56| but the timer does not reset because the gear is held in engaged position by the electromagnet 5| and the timer clockspring is not strong enough to run the motor back through the reduction gearing. The timer will, however, reset whenever the electromagnet 5|| is deenergized, which occurs when the switch 468 is opened by forward movement of the ram |59.

At this time the elevator |62 is down so the switch 46| which is a normallyopen switch is closed. There is a batt 86 above the elevator |62 which is against the roller 366. As illustrated in Figure 25, the switch 364 has a normally open switch element 364a and a normally closed switch element 36412. With the batt 8U against the roller 366, the switch element 3641 is closed and the switch 364b is open. This provides a circuit to energize a relay 545 as follows: main line 53| by a branch line 546 to relay 545, then by a line 541 to switch element 364a and by a line 548 to switch 46| to switch 468 to branch line 546 to mainline 532.

The relay 545 being energized, it closes a, switch 556 `which energizes another relay 55| as follows: from main line 53| by a branch line 552 to a line 553 to relay 55|, by a line 554 and a line 555 to the switch 556, by a line 556 to a line 551 to the switch 5|2 to line 536 which is connected to the main line 532 as aforesaid.

'Ihis causes the elevator |62 to rise. The relay 55| closes a switch 566 which connects the branch line 552 to a line 562 which is connected to a solenoid 565 that is connected by a branch line 566 to'the main line 532, thus energizing the solenoid 565. I

Referring now to Figure 24, the solenoid 565 operates a valve member 561 in a casing 568 against a, spring 569. A pipe 518 may be connected to the city water supply and has a reducing valve 51| for regulating the effective water pressure. Pipe 518 is connected by a T union to a pipe 513 which leads to a valve port 514. The valve member 561 has two reduced portions 515 and 516. When the solenoid 565 is deenergized, the reduced portion 518 connects the port 514 to a port 511. Port 511 is connected by a pipe 518 and a pipe 519 to the channel 398 of the cylinder head 388. The pipes 518 and 519 are connected by parallel pipes 588 and 58| in the first of which is a check valve 582 and in the second of which is a hand operated valve 583. It will readily be seen that with the valve member 561 down, as shown, the piston 392 and the elevator |62 must move down or stay down.

The channel 389 of the cylinder head 381 is connected by a pipe 585 to a port 586 in the casing 568. With the valve member 561 down, the port 586 is connected by, the reduced portion 515 to a port 581 that is connected by a pipe 588 to a pipe 589 having a check valve 598. The pipe 589 is connected by a T union to a pipe 59| that may lead to the sewer or any other waste or discharge. A pump and oil reservoir may be substituted for the city water supply if desired,

portion 515 to connect the pressure port 514 to the port 586 that is connected to the pipe 585 leading to the channel 389 in the cylinder head 381 at the bottom of the cylinder 38|. This causes the piston 392 to rise, moving the elevator |62 up, and the up stroke of the elevator may be regulated by valve 583. Water exhausts from the cylinder 38| by way oi.' the channel 398, pipe 519, pipe 58| having valve 583, pipe 518, port 511, reduced portion 516 to a port 592 connected to a pipe 593 that connects to the pipe 589 having the check valve 598, the water discharging to the sewer, etc., through the pipe 59|.

It will be seen that the upstroke of the elevator |62 may be regulated by the hand operated valve 583 because the fluid can not move out through the check valve 582. However the down stroke of the elevator |62 is not so regulated because the iluid can move in through the check valve 582. This is a desirable feature because on the up stroke the elevator is carrying a batt 88 loaded with green (hence somewhat fragile) wheels 92, but on the down stroke the elevator |62 is carrying no ware and the stroke may be fast.

Referring again to the wiring diagram Figure 25, the switch 411 in the discharging conveyor |63 is connected by a branch line 595 to the main line 532. The other end of the switch 411 which is normally closed is connected by a line 596 to a two way hand operated switch 591 the switch pivot terminal 598 of which is connected to a line 599 that is connected to a switch 688 operated by the relay 55|. The switch 688 is further connected by a line 68| to the line 554 which goes to the relay 55|. Thus when the relay 545 is deenergized the above holding circuit nevertheless keeps the relay 55| energized. The

18 relay 545 is in fact deenergized when the elevator |62 moves up a short distance, because this action breaks the circuit to relay 545 at the switches 48| and 364a.

When the elevator |62 arrives at its top position, a batt 88 thereon hits the roller 424 which closes normally open switch 42|. 'I'his energizes a relay 684 in the following manner: vswitch 42| is connected by a branch line 685 to the main line 532. Switch 42| is likewise connected by a line 686 to a line 681 connected to the relay 684. The other end of the relay 684 isdirect gxinected by a branch line 688 to the main line Energization of the relay 604 starts the ram |59 to propel the batt 88 on the elevator 62. This occurs through energization of a ram operating solenoid 6|8 which is energized as follows: a branch line 6|| connects the solenoid 6|8 to the main line 532 while the other end of the solenoid 6|!) is connected by a line 6|2 to a switch 6|3 operated by the relay 684, the other end of the switch 6 I3 being connected by a branch line 6|4 to the main line 53|.

It is desirable that once the ram has started it shall not retreat until the batt with green ware has been moved oi the elevator |62 and a batt with red ware has emerged from the kiln onto the discharging conveyor |63. The elevator |62 should not go down while a batt is partly on it because this might spill the green ware 0E the batt or cause a jam when the next batt is raised. On the other hand the cycle should not go on unless a batt is emerging from the kiln at the right moment in the cycle. Also the relay 684, once energized, should continue to be energized even after the switch 42| is opened. Furthermore the elevator |62 should be maintained in its up position while the ramY |59 is moving forward, otherwise the Yware will be spilled. For these purposes we provide a holding circuit for relay 684 and certain interconnections between relays 55| and 684 and the elevator solenoid 565 which will now be described.

A branch line 6|5 connects one end of a switch 6|6 operated by the relay 55| to the main line 532. The other end of the switch 6|6 is connected by a line 6| 1 to a switch 6|8 which is connected by a short line 6|9 to the line 681. The switch 6|8 is operated by the relay 684, and thus a holding circuit for the relay 684 is established which will not be broken so long as the relay 55| remains energized. A branch line 628 connects a relay 684 operated switch 62| to a line 622 which is connected to the line 562 that is connected to the solenoid 565 controlling the elevator |62. Thus if the relay 55| should fail the elevator |62 nevertheless remains up.

When the switch 42| opens up which is supposed to happen when a batt 88 'has been pushed so far forward that it leaves the second roller 425, the making circuit for the relay 684 is lbroken. Nevertheless the above described holding circuit for the relay 684 is still maintained until the switch 411 is opened bya batt 88 emerging from the kiln. If these events occur in reverse order tothe above, the relay 684 is kept energized until the switch 42| is opened. But when both switches 42| and 411 are opened, the relay 55| is deenergized so the holding circuit for relay 684 is broken and it also is deenergized. Now the circuits for both of the solenoids 565 and 6|8 are broken and the ram |59l retreats while the elevator |62 goes down.

The ram |58 is governed by the solenoid 6I8 17 in that the ram |59 moves forward or stays in its furthest forward position so long as the solenoid |0 is energized. Just as in the case oi the elevator |62, the active or forward stroke of the ram takes place ata controlled rate of speed determined by the setting of a valve, while the return is rapid. Referring now to Figure 24, the hydraulic system to operate the piston |6| in 4 the cylinder |15 is identicalwith the hydraulic system to operate the piston 392 in the cylinder 29| so the description will not be repeated. The same numbering system is used for the various parts, pipe lines, ports and valves, in the six hundred series however instead of the five hundred series. Thus the main valve member operated by the solenoid 6|0 is valve member 661 and so on to the exhaust pipe 693. Certain parts are in common, as will readily be seen from Figure 24, for example the water supply pipe 510, the hand operated valve x51| and the pipe 59| leading to the sewer. The valve 51| provides means for regulating the return stroke of 'both pistons 992 and |8| so that the apparatus will not be damaged by too rapid descent of the elevator |62 or retreat of the ram |59.

We may provide pressure gauges for the hydraulic system such `as the gauge 695 in the line 695 and the gauge 696 in the line 619 to check the pressure. These are in the system for the ram |59 as it is important to control the movement of this ram, but the gauges also give information which applies to the operation of the elevator as well. We may also provide a pipe 691 with a pet cock 698 to drain the water from the pipe 605 in order toclear the line of air bubbles, and similar provision may be made for any other of the pipes but the system operates very well as shown.

As shown in Figure 8, the valve casing 566 and its counterpart 666 which support the similar solenoids 565 and 6|0 are supported by brackets 699 attached to the side of a-leg |9l. i

Referring again to Figure 25. when the ram |59 goes forward, the switch 408 is opened. This breaks the circuit energizing the timer electromagnet 5I therefore unmeshed and the clockspring of the timer returns the timer arm to an adjustable stop which determines the time interval of the timer. Deenergization of this timer magnet 5|| also permits the switch 4 I 3 to close and the switch 5|2 to open, under the inuence of a spring the same as in .all the relay operated switches hereof. The latch of the timer locks these switches, 5|2 open and 5|3 closed, and will hold them so until the arm of the timer next releases the latch. By the closing of switch 5|3 the circuit for the timer motor 50| is reestablished excepting that the switch 409 is open, Therefore, with the return of the ram |59 which closes the switch 408, not only is the electromagnet 5|| reenergized, but the timer motor 50| is restarted. For clarity these circuits will now be repeated: right hand top oi' Figure 25, branch line 540 takes current from the main line 532 and goes to the switch 406, `line 538 takes the current from the switch 406 to the hand switch 531 which should be closed to the right. line 536 takes the current to the line 535 which branches into lines 594^and 543,'*eth former leading to one side oi'gthe electromagnet v5|| and the latter leading to one-sident the motor 50|. The circuit is completed to the electromagnet 5| I by branch line 533 from the main line 53|, and the circuit is completed to the motor 50| by the branch line'533, line 54|, switch 5l3 and line 'I'he moveable gear in the timer is 18 542. The timer will now measure the desired time interval while further events of the operating cycle continue.' These further events will have taken place and the kiln mechanism will be at rest before the timer arm again starts the cycle by tripping the latch to close the switch 5|2.

It will be remembered that there are two switches 460 and 464 in the discharging conveyor |63 which control it. Referring now to the lower part of Figure 26, a branch line connects a relay 10| to the main line 524. The other end of the relay 10| is connected to the switch 460 by means of a line 102 while the other end of the switch 460 is connected to the main line 525 by means of a branch line 103. Thus when the switch 460 is closed by a batt 90 emerging from the tunnel 35, the relay 10| is energized. This action closes a switch 104 which is connected by a branch line 105 to the main line 525, the other side of the switch 104 being connected to the motor 45| by a line 106, and the other side oi the motor 45| being connected to the main line 524 by a branch line 101. Thus, energization of the relay 10| responsive to closing of the switch 460 causes energization of the motor 45|, and the discharging conveyor |63 starts to operate.

It is the action of the discharging conveyor |63 which moves a batt 80 into contact with the roller 419 of the normally closed switch 411 but the switches 460 and 411 are so close together that there is little lapse of time between the closing of the switch 460 and the opening of the switch 411. Now, however, the batt 80 has left the switch 460, so it automatically opens. This however does not deenergize the relay 10| for the following reason: a branch line 108 connects the switch 464 (which is normally closed) to the main line 525, while a line 109 connects the other end of the switch 464 to a switch 1|0 which is operated by the relay 10|. The other side of the switch 1|0 is connected by a line 1li to the line 102 and therefore to the relay 10|. In that way current keeps flowing to the relay 10|, for the other side thereof is permanently connected to the main line 524 by the branch line i100.

Now when the batt 80 which just came onto the discharging conveyor |63 hits the roller 462 the switch 664 is opened and this action opens the holding circuit of the relay 10|, which goes dead, so the switch 104 is opened and therefore the conveyor motor 45| stops. When the next batt 60 restarts the conveyor |63 the old batt 80 is moved oir the roller 462 of the switch 464 thus allowing it to close and this happens before the switch 460 opens. The reason is there is a slight coasting of the conveyor |63 after the energy is cut offpreferably the motor 45| has no automatic brake. The coasting of the motor 45|' `and the conveyor |63 could be great enough to noid 6|0 and the elevator |62 has gonedown, due

to deenergization of the solenoid-565, the feeding conveyor operates to carry a new batt80 over the elevator |62.

alive at this time for the following reason: in the..V

We provide a relay 1|5 which is previous operation of the kiln a lbatt struck the roller 296 of the switch 2'98 and operated it. This .1

switch 298 has a, normally open switch element 298a and a normally closed switch element 296b. When actuated the element 298a closes a circuit acaaoas i@ and the element 298b,. opens a circuit. By the closing of the element a a circuit is established through the relay 1|5 to energize it in the following manner. A branch line 120 is connected to the main line 524 and goes to one side of both of the switch elements 268m and 298D. Aline 52| goes from the other side of the switch element 288a to the relay 1 5. The other side of the relay 1|5 is connected by a. line 122 to one side of the normally closed switch 35i) which is mounted part way out in the feeding conveyor |6|, A branch line 123 connects the other side of the switch 350 to the main line 525. Thus the relay 1|5 is energized when a batt 80 strikes theroller 296. A holding circuit is provided for this relay 1|5 in case the batt 80 bounces back. A line 124 connected to the branch 120 bypasses the switch 298 going to a switch '|25 operated by the relay 1|5. The other end of the switch 125 is directly connected to the line 12| and thus the holding circuit is established.

This relay 1|5 remains energized while the feeding conveyor |6| is stationary since the only switch to open the holding circuit is the normally closed switch 350 which is only operated by a batt 80 moving on the feeding conveyor |6|. Now when the ram |50 has retreated the full length of its stroke, it closes the switch 408. When the elevator |62 has moved to the bottom it closes the switch 40|. When there is no batt over the elevator the switch element 364b is closed because it is a normally closed switch. These three switches being closed establish that conditions are right for the feeding conveyor |6| to `move. The rst step is automatic energization of a relay 130 as follows.

The branch line 540 leads to the switch 408 and the switch 408 is connected to the switch 40| by part of the line 538 and by a short line 13|. The switch 40| is connected to switch element 364b which is connected by a line 132 and a line 133 to a switch 134 operated by the relay 1|5. The other side of the switch 134 is connected by a line 135 to the relay 130 the other side of which is connected by a branch line 136 to the main line 53|.

Immediately the relay 130 is energized it establishes a holding circuit for itself. This is by way of a line 138 connecting the line 132 to a switch 139 operated by the relay 132, the other side of the switch 130 being connected by a line 140 to the line 135.

Energization of the relay 130 closes circuits to the solenoid 323 which operates the transferrer or mechanical switch |65 and to the motor 28| which drives the feeding conveyor |6|. From main line 53| a branch line 145 runs to a switch 146 operated by the relay 130, and from the other side of the switch 146 aline 141 runs to the solenoid 323 which is also connected by a. branch line 148 to the main line 532. From main line 53| a branch line 150 runs to a switch- 15| operated by the relay 130, and from the other side of the switch a line 152 runs to the motor 28|. From the'other side of the motor 28| a line 154 runs to a switch 155 also operated by the relay 130, and the other side of the switch 155 is connected to the main line 532 by a branch line 156.

It will be seen that the transferrer |65 and the feeding conveyor |6| start practically simultaneously. The transferrer |65, when operated, gently lowers the batt which is resting upon it onto the chains 290 of the feeding conveyor |6|. These chains 290, since the motor 28| was energized, move the batt 80 that was just deposited upon them which soon trips the normally closed switch 350. This action deenergizes the relay 1|5 and opens its holding circuit through the switch 125. The relay 130, however, remains energized by its holding circuit through the switch 139, so the motor 28| keeps running. As the batt 80 moves off the roller 352 of the switch 350 this switch closes. The feeding conveyor |6| keeps running until a batt 80 thereon (not necessarily the same one that was just lowered by the transferrer |65 but possibly so) hits the roller 366 of the switch 364, which opens the switch element 364b and closes the switch element 364a. Opening of the switch element 3641 cuts both the making circuit and the holding circuit of the relay 130 and thereupon the conveyor |6| stops and the transferrer |65 rises ready to receive a batt from the loading conveyor |60. As previously stated there may be only one batt on or above the feeding conveyor |6| after the elevator |62 has gone upv and the loading conveyor has operated, or there may be several. Care should be taken, however, that there are not so many batts on the feeding conveyor |6| that one comes to rest on the roller 352 of the switch 350 thus keeping it open, since this switch should be closed by the time the feeding conveyor |6| comes to a stop to permit the kiln to operate for the following cycle.

When a batt 80 strikes the roller 366 of the switch 364 it closes the switch element 364m at the same time that it opens the switch element 36412 as above described. This, as above stated, stops the feeding conveyor |6| and raises the transferrer which is now ready to receive a new batt from the loading conveyor which is now to operate. The batt 80 which hit the roller 366 is right above the elevator |62 ready to be lifted in the next cycle.

When the switch element 364a closes, current can run from main line 532 via branch line 540, switch 408, part of line '538, short line 13 i, switch 40|, line 548, switch 364a, line 541 to the relay 545, then by the branch line 546 to the line 53|. This energizes the relay 545 and there is no holding circuit because if the batt 60 over the elevator is not in just the right position it is desired that the cycle be stopped by the opening of the switch 364a.

Energization of the relay 545 causes, at this time, energization of a relay 160 as follows: a branch line 16| is connected to the main line 532 and to a switch 162 operated by the relay 545. A line 163 goes from the other side of the switch 162 to a switch 164 controlled by the relay 1|5. This switch 164 is a normally closed switch contra to all the other relay switches which are normally open switches (except that magnet 5|| switch 5|3 is also normally closed). From the other side of the switch 164 a line 165 leads to the relay 160. 'I'he other side of the relay 160 is connected by a line 161 to the switch element 29817 which is now closed because there is no batt 80 on the transferrer |65. As previously stated the switch element 2981) is connected by line to the main line 524, so the circuit through the relay is complete. In this case the circuit is from main line 532 to main line 524 but this is a good power circuit and when the hand switch 526 is opened the circuit will be broken.

Relay 160 has a, holding circuit using line 120, switch 2981i, line 161 and part of line 165, the remainder being a line 110, a relay switch 11|, a line 112, a line 113 and the branch line 540.

Relay 160 operates the motor 230 which runs 

